1. Field of the Invention
The present invention relates to a reaction apparatus in which a reactant is provided to cause a reaction of the reactant, and particularly a reaction apparatus which comprises a chemical reaction unit causing a reaction by heating the chemical reaction unit to a predetermined temperature.
2. Description of the Related Art
Conventionally, in every field of consumer and industrial products, various chemical batteries have been used. For example, the chemical batteries are a primary battery such as an alkaline battery and a manganese battery, and are a secondary battery such as a nickel-cadmium storage battery, a nickel-hydrogen storage battery, and a lithium-ion battery. As opposed to these chemical batteries, in recent years, a research and a development for putting the following power supply system into practical use have been actively performed. The power supply system is a system using a fuel cell which has a less influence (load) on the environment and is capable of realizing energy utilization efficiency extremely as high as approximately 30 to 40%. Moreover, there have also been progressed a research and a development for downsizing the power supply system using the fuel cell as described above to make the power supply system applicable as a power supply unit taking place of such a secondary battery of a mobile information terminal or of a mobile instrument such as a notebook personal computer, thereby extending a usable time thereof.
Incidentally, in the power supply system using the fuel cell, for example, there is a system in which a liquid fuel having hydrogen atom in the composition thereof, such as alcohols and gasoline, is vaporized and the hydrogen is taken out by reforming the vaporized liquid fuel, and the hydrogen gas taken out is provided to the fuel cell in order to generate electricity. In this case, a reaction apparatus which comprises a chemical reaction unit such as a vaporizer for vaporizing the liquid fuel and water, and a reformer for taking out the hydrogen by causing reform reaction between the vaporized liquid fuel and high-temperature steam is required.
Here, the chemical reaction unit such as a vaporizer, a reformer, and the like are heated. By setting the chemical reaction unit to the predetermined temperature (for example, approximately 80 to 120° C. in the vaporizer, and approximately 250 to 400° C. in the reformer), the predetermined chemical reaction proceeds. Therefore, the temperature of a chemical reaction unit such as a vaporizer, a reformer, and the like is maintained at the needed temperature, the heat release to outside is restricted, and the chemical reaction unit is housed in a hollow heat insulation package in order to reduce the loss of the heat energy and to improve the heat efficiency. For this reason, these chemical reaction units are set at comparatively high temperature. However, these chemical reaction units are housed in the insulation package and the heat from those units are prevented from leaking.
However, in case that abnormality occurs in the reaction apparatus, for example, when the heat insulation package is broken by being applied to some impact from the outside, when the heat insulation package is disassembled in an unauthorized manner, when abnormality occurs in the reformer and the like to raise the temperatures thereof, and when abnormality occurs in control for the reformer and the like to raise the temperatures thereof, there is some possibility that the heat of the chemical reaction unit may leak to the outside of the heat insulation package.